A Brazilian journalist missing in Libya for a week has been jailed - but reports claim he is about to be released.

Libya's ambassador to Brazil told Brazilian senators that reporter Andrei Netto is about to be freed, the Estado de S Paulo newspaper said on its website.

But there was no word on the whereabouts of Guardian correspondent Ghaith Abdul-Ahad, who had been with Mr Netto.

Libyan Ambassador Salem Omar Abdullah Al-Zubaidi said Mr Netto was arrested because of mistakes he made in forms he filled out to enter Libya, according to senators quoted on the website.

Brazilian president Dilma Rousseff has ordered her foreign ministry to take the steps needed to ensure the journalist's release, the president's office said in a statement. It added that Mr Netto is being held in a jail in the Libyan town of Sabratha.